Search

Keshan disease (KD) is a type of endemic cardiomyopathy with an unknown cause. It is primarily found in areas in China with low selenium levels, from northeast to southwest. The nutritional biogeochemical etiology hypothesis suggests that selenium deficiency is a major factor in KD development. Selenium is important in removing free radicals and protecting cells and tissues from peroxide-induced damage. Thus, low environmental selenium may affect the selenium level within the human body, and selenium level differences are commonly observed between healthy people in KD and nonKD areas. From the 1970s to the 1990s, China successfully reduced KD incidence in endemic KD areas through a selenium supplementation program. After years of implementing prevention and control measures, the selenium level of the population in the KD areas has gradually increased, and the prevalence of KD in China has remained low and stable in recent years. Currently, the pathogenesis of KD remains vague, and the effect of selenium supplementation on the prognosis of KD still needs further study. This paper comprehensively reviews selenium deficiency and its connection to KD. Thus, this study aims to offer novel ideas and directions to effectively prevent and treat KD in light of the current situation.

Selecting one presently popularized winter wheat cultivar (Zhengmai 9023) and two cultivars (Abo and Fengchan 3) introduced in the 1950s and 1960s in Huang-Huai Plain as test materials, and by using minirhizotron technique, this paper studied the live root length, root diameter distribution, and net root growth rate of the cultivars. Fine roots with a diameter from 0.05 mm to 0.25 mm occupied the majority of the whole root system, and the fine roots with a diameter less than 0.5 mm accounted for 98% of the live root length. The average root diameter varied with plant growth, the variation range being 0.15 - 0.22 mm, and no significant difference was observe among the cultivars. The live root length was significantly positively correlated root number, suggesting that root number was the main factor for the increase of live root length. The most vigorous growth period of the roots was from reviving to jointing stage, and Abo and Fengchan 3 had a longer period increased root vitality, as compared with Zhengmai 9023. For Zhengmai 9023, its fine roots with a diameter more than 0.1 mm had an increasing proportion after jointing stage, which was helpful for improving plant resistance, root activity, and grain-filling at late growth stages.

Objective: Understand the public's current attitudes and knowledge about suicide and, thus, provide essential information to the development of targeted public education programs-important components of the suicide prevention effort., Methods: Seventeen mental health professionals who were extensively trained in the methods of conducting focus groups used a pre-tested focus group outline on attitudes and knowledge about suicide to conduct 101 focus groups and 18 individual in-depth interviews with a total of 842 community respondents from 6 regions in northern China. The focus groups and in-depth interviews were audio-taped, transcribed and analyzed using the QSR Nvivo text analysis software., Results: Most respondents believed that suicide was a greater problem in rural areas and among women and identified physical illnesses, economic problems and interpersonal conflicts (particularly family conflicts) as the main causes of suicide. Rural residents and women were believed to exhibit impulsive suicidal behavior because of their personal limitations and over-sensitiveness. Most thought that suicide was understandable and a small proportion felt that it was acceptable behavior in certain circumstances. Almost all felt that suicide resulted in the stigmatization and a loss of 'face' for the family. Most believed that one should show concern for persons who have suicidal behavior and their family members and expressed a willingness to have superficial social relationships with them but were unwilling to establish close personal relations with them. The vast majority believed that suicide was either very difficult or impossible to prevent., Conclusions: In China the community is tolerant, sympathetic and, in some cases, accepting of suicide but there remains a substantial underlying stigmatization of suicide. Community members have some misunderstandings about suicide; the most obvious misunderstanding is the underestimation of the importance of mental illness as a cause of suicide. The content of public health messages used in suicide prevention programs should be developed by combining findings from both qualitative and quantitative research.

Recent studies have revealed a high prevalence of leukocytospermia (> 1 x 10(6) white blood cells ml-1 semen) in male infertility patients in the USA and certain European countries, and have implicated white blood cells as a cause of infertility. Since leukocytospermia may often be attributed to male genital-tract infections, its prevalence could vary widely in different populations depending on factors such as sexual practices and the prevalence of sexually transmitted pathogens. In the study described here the incidence of leukocytospermia was determined in a group of 101 male infertility patients and a small reference group of normal fertile men in Beijing, China. Seminal white blood cells (WBC) and WBC sub-populations were enumerated by peroxidase staining and immunohistological assay. Eight out of 101 (7.9%) samples from infertility patients and 0/10 samples from fertile donors were leukocytospermic. The incidence of leukocytospermia in the Chinese infertility patients was considerably lower than the 23% incidence observed in a recent study of infertility patients in the USA using a similar technique. All but one of the patients with leukocytospermia had a poor sperm count and/or poor sperm motility. However, due to the low incidence of leukocytospermia and the small number of patients in this group, a statistically significant association between leukocytospermia and poor semen quality was not attained. The simple peroxidase test correlated well with the more expensive and technically demanding immunohistological assay for detection of white blood cells in semen.